The 'Eat to the Beat' Concert Series has now been added to FastPass+ for Epcot. 'Eat to the Beat' will be listed as a Tier 1 option, meaning you can choose one from; Soarin', Test Track, Living with the Land, IllumiNations and 'Eat to the Beat'. You can book these special FastPasses like any others; either online using My Disney Experience, or via an in-park kiosk.
There will be a FastPass+ return queue to the theater with the line opening 20 minutes before the scheduled start time. Eat to the Beat begins on 25th September 2015.